I recently upgraded my account on Vimeo to be able to get my direct source file on a MP4 extension. Vimeo showed me several quality available for each of my videos.
I was wondering if there is a way to serve the user a specific quality based on its connexion?
By default I serve a SD quality video.
In the same response as the MP4 video file direct links, you should see an .m3u8 link. This link is an HLS manifest file that is used for adaptive streaming. You'll need to check if the player you're using supports HLS.
HLS documentation can be found here: https://developer.apple.com/streaming/